From 4f157a8b81b88514a6d1fb384a57e82cc3c7ad0d Mon Sep 17 00:00:00 2001
From: David Tolnay <dtolnay@gmail.com>
Date: Mon, 12 Dec 2022 14:37:41 -0800
Subject: [PATCH] Prevent build.rs rerunning unnecessarily on all source
 changes

---
 serde/build.rs                  | 2 ++
 serde_derive/build.rs           | 2 ++
 serde_derive_internals/build.rs | 3 +++
 serde_test/build.rs             | 2 ++
 test_suite/build.rs             | 2 ++
 5 files changed, 11 insertions(+)

diff --git a/serde/build.rs b/serde/build.rs
index 4fab6ad0f..ccbddd273 100644
--- a/serde/build.rs
+++ b/serde/build.rs
@@ -6,6 +6,8 @@ use std::str::{self, FromStr};
 // opening a GitHub issue if your build environment requires some way to enable
 // these cfgs other than by executing our build script.
 fn main() {
+    println!("cargo:rerun-if-changed=build.rs");
+
     let minor = match rustc_minor_version() {
         Some(minor) => minor,
         None => return,
diff --git a/serde_derive/build.rs b/serde_derive/build.rs
index 2aece0469..1249dab59 100644
--- a/serde_derive/build.rs
+++ b/serde_derive/build.rs
@@ -6,6 +6,8 @@ use std::str;
 // opening a GitHub issue if your build environment requires some way to enable
 // these cfgs other than by executing our build script.
 fn main() {
+    println!("cargo:rerun-if-changed=build.rs");
+
     let minor = match rustc_minor_version() {
         Some(minor) => minor,
         None => return,
diff --git a/serde_derive_internals/build.rs b/serde_derive_internals/build.rs
index b2a2d04ab..25b5ef313 100644
--- a/serde_derive_internals/build.rs
+++ b/serde_derive_internals/build.rs
@@ -1,6 +1,9 @@
 use std::path::Path;
 
 fn main() {
+    println!("cargo:rerun-if-changed=build.rs");
+    println!("cargo:rerun-if-changed=src/mod.rs");
+
     // Sometimes on Windows the git checkout does not correctly wire up the
     // symlink from serde_derive_internals/src to serde_derive/src/internals.
     // When this happens we'll just build based on relative paths within the git
diff --git a/serde_test/build.rs b/serde_test/build.rs
index f7ca97417..b7f69d98f 100644
--- a/serde_test/build.rs
+++ b/serde_test/build.rs
@@ -6,6 +6,8 @@ use std::str::{self, FromStr};
 // opening a GitHub issue if your build environment requires some way to enable
 // these cfgs other than by executing our build script.
 fn main() {
+    println!("cargo:rerun-if-changed=build.rs");
+
     let minor = match rustc_minor_version() {
         Some(minor) => minor,
         None => return,
diff --git a/test_suite/build.rs b/test_suite/build.rs
index 957af7629..3ace7d3db 100644
--- a/test_suite/build.rs
+++ b/test_suite/build.rs
@@ -19,6 +19,8 @@ fn has_cargo_expand() -> bool {
 }
 
 fn main() {
+    println!("cargo:rerun-if-changed=build.rs");
+
     if cfg!(feature = "expandtest") && has_cargo_expand() {
         println!("cargo:rustc-cfg=expandtest");
     }